diff --git a/wire/protocol.go b/wire/protocol.go
index c767a5fa..8cc9838a 100644
--- a/wire/protocol.go
+++ b/wire/protocol.go
@@ -72,9 +72,20 @@ const (
 	// and transactions including witness data (BIP0144).
 	SFNodeWitness
 
+	// SFNodeXthin is a flag used to indicate a peer supports xthin blocks.
+	SFNodeXthin
+
+	// SFNodeBit5 is a flag used to indicate a peer supports a service
+	// defined by bit 5.
+	SFNodeBit5
+
 	// SFNodeCF is a flag used to indicate a peer supports committed
 	// filters (CFs).
 	SFNodeCF
+
+	// SFNode2X is a flag used to indicate a peer is running the Segwit2X
+	// software.
+	SFNode2X
 )
 
 // Map of service flags back to their constant names for pretty printing.
@@ -83,7 +94,10 @@ var sfStrings = map[ServiceFlag]string{
 	SFNodeGetUTXO: "SFNodeGetUTXO",
 	SFNodeBloom:   "SFNodeBloom",
 	SFNodeWitness: "SFNodeWitness",
+	SFNodeXthin:   "SFNodeXthin",
+	SFNodeBit5:    "SFNodeBit5",
 	SFNodeCF:      "SFNodeCF",
+	SFNode2X:      "SFNode2X",
 }
 
 // orderedSFStrings is an ordered list of service flags from highest to
@@ -93,7 +107,10 @@ var orderedSFStrings = []ServiceFlag{
 	SFNodeGetUTXO,
 	SFNodeBloom,
 	SFNodeWitness,
+	SFNodeXthin,
+	SFNodeBit5,
 	SFNodeCF,
+	SFNode2X,
 }
 
 // String returns the ServiceFlag in human-readable form.
diff --git a/wire/protocol_test.go b/wire/protocol_test.go
index 639dcc9f..60bd0533 100644
--- a/wire/protocol_test.go
+++ b/wire/protocol_test.go
@@ -17,8 +17,11 @@ func TestServiceFlagStringer(t *testing.T) {
 		{SFNodeGetUTXO, "SFNodeGetUTXO"},
 		{SFNodeBloom, "SFNodeBloom"},
 		{SFNodeWitness, "SFNodeWitness"},
+		{SFNodeXthin, "SFNodeXthin"},
+		{SFNodeBit5, "SFNodeBit5"},
 		{SFNodeCF, "SFNodeCF"},
-		{0xffffffff, "SFNodeNetwork|SFNodeGetUTXO|SFNodeBloom|SFNodeWitness|SFNodeCF|0xffffffe0"},
+		{SFNode2X, "SFNode2X"},
+		{0xffffffff, "SFNodeNetwork|SFNodeGetUTXO|SFNodeBloom|SFNodeWitness|SFNodeXthin|SFNodeBit5|SFNodeCF|SFNode2X|0xffffff00"},
 	}
 
 	t.Logf("Running %d tests", len(tests))